/*

 Holder - 1.9 - client side image placeholders
 (c) 2012-2013 Ivan Malopinsky / http://imsky.co

 Provided under the Apache 2.0 License: http://www.apache.org/licenses/LICENSE-2.0
 Commercial use requires attribution.

 */

var Holder = Holder || {};
(function (app, win) {

  var preempted = false,
    fallback = false,
    canvas = document.createElement('canvas');

//getElementsByClassName polyfill
  document.getElementsByClassName || (document.getElementsByClassName = function (e) {
    var t = document, n, r, i, s = [];
    if (t.querySelectorAll)return t.querySelectorAll("." + e);
    if (t.evaluate) {
      r = ".//*[contains(concat(' ', @class, ' '), ' " + e + " ')]", n = t.evaluate(r, t, null, 0, null);
      while (i = n.iterateNext())s.push(i)
    } else {
      n = t.getElementsByTagName("*"), r = new RegExp("(^|\\s)" + e + "(\\s|$)");
      for (i = 0; i < n.length; i++)r.test(n[i].className) && s.push(n[i])
    }
    return s
  })

//getComputedStyle polyfill
  window.getComputedStyle || (window.getComputedStyle = function (e, t) {
    return this.el = e, this.getPropertyValue = function (t) {
      var n = /(\-([a-z]){1})/g;
      return t == "float" && (t = "styleFloat"), n.test(t) && (t = t.replace(n, function () {
        return arguments[2].toUpperCase()
      })), e.currentStyle[t] ? e.currentStyle[t] : null
    }, this
  })

//http://javascript.nwbox.com/ContentLoaded by Diego Perini with modifications
  function contentLoaded(n, t) {
    var l = "complete", s = "readystatechange", u = !1, h = u, c = !0, i = n.document, a = i.documentElement, e = i.addEventListener ? "addEventListener" : "attachEvent", v = i.addEventListener ? "removeEventListener" : "detachEvent", f = i.addEventListener ? "" : "on", r = function (e) {
      (e.type != s || i.readyState == l) && ((e.type == "load" ? n : i)[v](f + e.type, r, u), !h && (h = !0) && t.call(n, null))
    }, o = function () {
      try {
        a.doScroll("left")
      } catch (n) {
        setTimeout(o, 50);
        return
      }
      r("poll")
    };
    if (i.readyState == l)t.call(n, "lazy"); else {
      if (i.createEventObject && a.doScroll) {
        try {
          c = !n.frameElement
        } catch (y) {
        }
        c && o()
      }
      i[e](f + "DOMContentLoaded", r, u), i[e](f + s, r, u), n[e](f + "load", r, u)
    }
  };

//https://gist.github.com/991057 by Jed Schmidt with modifications
  function selector(a) {
    a = a.match(/^(\W)?(.*)/);
    var b = document["getElement" + (a[1] ? a[1] == "#" ? "ById" : "sByClassName" : "sByTagName")](a[2]);
    var ret = [];
    b != null && (b.length ? ret = b : b.length == 0 ? ret = b : ret = [b]);
    return ret;
  }

//shallow object property extend
  function extend(a, b) {
    var c = {};
    for (var d in a)c[d] = a[d];
    for (var e in b)c[e] = b[e];
    return c
  }

//hasOwnProperty polyfill
  if (!Object.prototype.hasOwnProperty)
    Object.prototype.hasOwnProperty = function (prop) {
      var proto = this.__proto__ || this.constructor.prototype;
      return (prop in this) && (!(prop in proto) || proto[prop] !== this[prop]);
    }

  function text_size(width, height, template) {
    var dimension_arr = [height, width].sort();
    var maxFactor = Math.round(dimension_arr[1] / 16),
      minFactor = Math.round(dimension_arr[0] / 16);
    var text_height = Math.max(template.size, maxFactor);
    return {
      height: text_height
    }
  }

  function draw(ctx, dimensions, template, ratio) {
    var ts = text_size(dimensions.width, dimensions.height, template);
    var text_height = ts.height;
    var width = dimensions.width * ratio, height = dimensions.height * ratio;
    var font = template.font ? template.font : "sans-serif";
    canvas.width = width;
    canvas.height = height;
    ctx.textAlign = "center";
    ctx.textBaseline = "middle";
    ctx.fillStyle = template.background;
    ctx.fillRect(0, 0, width, height);
    ctx.fillStyle = template.foreground;
    ctx.font = "bold " + text_height + "px " + font;
    var text = template.text ? template.text : (dimensions.width + "x" + dimensions.height);
    if (ctx.measureText(text).width / width > 1) {
      text_height = template.size / (ctx.measureText(text).width / width);
    }
    //Resetting font size if necessary
    ctx.font = "bold " + (text_height * ratio) + "px " + font;
    ctx.fillText(text, (width / 2), (height / 2), width);
    return canvas.toDataURL("image/png");
  }

  function render(mode, el, holder, src) {
    var dimensions = holder.dimensions,
      theme = holder.theme,
      text = holder.text ? decodeURIComponent(holder.text) : holder.text;
    var dimensions_caption = dimensions.width + "x" + dimensions.height;
    theme = (text ? extend(theme, {text: text}) : theme);
    theme = (holder.font ? extend(theme, {font: holder.font}) : theme);

    var ratio = 1;
    if (window.devicePixelRatio && window.devicePixelRatio > 1) {
      ratio = window.devicePixelRatio;
    }

    if (mode == "image") {
      el.setAttribute("data-src", src);
      el.setAttribute("alt", text ? text : theme.text ? theme.text + " [" + dimensions_caption + "]" : dimensions_caption);

      if (fallback || !holder.auto) {
        el.style.width = dimensions.width + "px";
        el.style.height = dimensions.height + "px";
      }

      if (fallback) {
        el.style.backgroundColor = theme.background;

      }
      else {
        el.setAttribute("src", draw(ctx, dimensions, theme, ratio));
      }
    } else {
      if (!fallback) {
        el.style.backgroundImage = "url(" + draw(ctx, dimensions, theme, ratio) + ")";
        el.style.backgroundSize = dimensions.width + "px " + dimensions.height + "px";
      }
    }
  };

  function fluid(el, holder, src) {
    var dimensions = holder.dimensions,
      theme = holder.theme,
      text = holder.text;
    var dimensions_caption = dimensions.width + "x" + dimensions.height;
    theme = (text ? extend(theme, {
      text: text
    }) : theme);

    var fluid = document.createElement("div");

    fluid.style.backgroundColor = theme.background;
    fluid.style.color = theme.foreground;
    fluid.className = el.className + " holderjs-fluid";
    fluid.style.width = holder.dimensions.width + (holder.dimensions.width.indexOf("%") > 0 ? "" : "px");
    fluid.style.height = holder.dimensions.height + (holder.dimensions.height.indexOf("%") > 0 ? "" : "px");
    fluid.id = el.id;

    el.style.width = 0;
    el.style.height = 0;

    if (theme.text) {
      fluid.appendChild(document.createTextNode(theme.text))
    } else {
      fluid.appendChild(document.createTextNode(dimensions_caption))
      fluid_images.push(fluid);
      setTimeout(fluid_update, 0);
    }

    el.parentNode.insertBefore(fluid, el.nextSibling)

    if (window.jQuery) {
      jQuery(function ($) {
        $(el).on("load", function () {
          el.style.width = fluid.style.width;
          el.style.height = fluid.style.height;
          $(el).show();
          $(fluid).remove();
        });
      })
    }
  }

  function fluid_update() {
    for (i in fluid_images) {
      if (!fluid_images.hasOwnProperty(i)) continue;
      var el = fluid_images[i],
        label = el.firstChild;

      el.style.lineHeight = el.offsetHeight + "px";
      label.data = el.offsetWidth + "x" + el.offsetHeight;
    }
  }

  function parse_flags(flags, options) {

    var ret = {
      theme: settings.themes.gray
    }, render = false;

    for (sl = flags.length, j = 0; j < sl; j++) {
      var flag = flags[j];
      if (app.flags.dimensions.match(flag)) {
        render = true;
        ret.dimensions = app.flags.dimensions.output(flag);
      } else if (app.flags.fluid.match(flag)) {
        render = true;
        ret.dimensions = app.flags.fluid.output(flag);
        ret.fluid = true;
      } else if (app.flags.colors.match(flag)) {
        ret.theme = app.flags.colors.output(flag);
      } else if (options.themes[flag]) {
        //If a theme is specified, it will override custom colors
        ret.theme = options.themes[flag];
      } else if (app.flags.text.match(flag)) {
        ret.text = app.flags.text.output(flag);
      } else if (app.flags.font.match(flag)) {
        ret.font = app.flags.font.output(flag);
      }
      else if (app.flags.auto.match(flag)) {
        ret.auto = true;
      }
    }

    return render ? ret : false;

  };

  if (!canvas.getContext) {
    fallback = true;
  } else {
    if (canvas.toDataURL("image/png")
        .indexOf("data:image/png") < 0) {
      //Android doesn't support data URI
      fallback = true;
    } else {
      var ctx = canvas.getContext("2d");
    }
  }

  var fluid_images = [];

  var settings = {
    domain: "holder.js",
    images: "img",
    bgnodes: ".holderjs",
    themes: {
      "gray": {
        background: "#eee",
        foreground: "#aaa",
        size: 12
      },
      "social": {
        background: "#3a5a97",
        foreground: "#fff",
        size: 12
      },
      "industrial": {
        background: "#434A52",
        foreground: "#C2F200",
        size: 12
      }
    },
    stylesheet: ".holderjs-fluid {font-size:16px;font-weight:bold;text-align:center;font-family:sans-serif;margin:0}"
  };


  app.flags = {
    dimensions: {
      regex: /^(\d+)x(\d+)$/,
      output: function (val) {
        var exec = this.regex.exec(val);
        return {
          width: +exec[1],
          height: +exec[2]
        }
      }
    },
    fluid: {
      regex: /^([0-9%]+)x([0-9%]+)$/,
      output: function (val) {
        var exec = this.regex.exec(val);
        return {
          width: exec[1],
          height: exec[2]
        }
      }
    },
    colors: {
      regex: /#([0-9a-f]{3,})\:#([0-9a-f]{3,})/i,
      output: function (val) {
        var exec = this.regex.exec(val);
        return {
          size: settings.themes.gray.size,
          foreground: "#" + exec[2],
          background: "#" + exec[1]
        }
      }
    },
    text: {
      regex: /text\:(.*)/,
      output: function (val) {
        return this.regex.exec(val)[1];
      }
    },
    font: {
      regex: /font\:(.*)/,
      output: function (val) {
        return this.regex.exec(val)[1];
      }
    },
    auto: {
      regex: /^auto$/
    }
  }

  for (var flag in app.flags) {
    if (!app.flags.hasOwnProperty(flag)) continue;
    app.flags[flag].match = function (val) {
      return val.match(this.regex)
    }
  }

  app.add_theme = function (name, theme) {
    name != null && theme != null && (settings.themes[name] = theme);
    return app;
  };

  app.add_image = function (src, el) {
    var node = selector(el);
    if (node.length) {
      for (var i = 0, l = node.length; i < l; i++) {
        var img = document.createElement("img")
        img.setAttribute("data-src", src);
        node[i].appendChild(img);
      }
    }
    return app;
  };

  app.run = function (o) {
    var options = extend(settings, o), images = [];

    if (options.images instanceof window.NodeList) {
      imageNodes = options.images;
    }
    else if (options.images instanceof window.Node) {
      imageNodes = [options.images];
    }
    else {
      imageNodes = selector(options.images);
    }

    if (options.elements instanceof window.NodeList) {
      bgnodes = options.bgnodes;
    }
    else if (options.bgnodes instanceof window.Node) {
      bgnodes = [options.bgnodes];
    }
    else {
      bgnodes = selector(options.bgnodes);
    }

    preempted = true;

    for (i = 0, l = imageNodes.length; i < l; i++) images.push(imageNodes[i]);

    var holdercss = document.getElementById("holderjs-style");

    if (!holdercss) {
      holdercss = document.createElement("style");
      holdercss.setAttribute("id", "holderjs-style");
      holdercss.type = "text/css";
      document.getElementsByTagName("head")[0].appendChild(holdercss);
    }

    if (holdercss.styleSheet) {
      holdercss.styleSheet += options.stylesheet;
    }
    else {
      holdercss.textContent += options.stylesheet;
    }

    var cssregex = new RegExp(options.domain + "\/(.*?)\"?\\)");

    for (var l = bgnodes.length, i = 0; i < l; i++) {
      var src = window.getComputedStyle(bgnodes[i], null)
        .getPropertyValue("background-image");
      var flags = src.match(cssregex);
      if (flags) {
        var holder = parse_flags(flags[1].split("/"), options);
        if (holder) {
          render("background", bgnodes[i], holder, src);
        }
      }
    }

    for (var l = images.length, i = 0; i < l; i++) {
      var src = images[i].getAttribute("src") || images[i].getAttribute("data-src");
      if (src != null && src.indexOf(options.domain) >= 0) {
        var holder = parse_flags(src.substr(src.lastIndexOf(options.domain) + options.domain.length + 1)
          .split("/"), options);
        if (holder) {
          if (holder.fluid) {
            fluid(images[i], holder, src);
          } else {
            render("image", images[i], holder, src);
          }
        }
      }
    }
    return app;
  };

  contentLoaded(win, function () {
    if (window.addEventListener) {
      window.addEventListener("resize", fluid_update, false);
      window.addEventListener("orientationchange", fluid_update, false);
    } else {
      window.attachEvent("onresize", fluid_update)
    }
    preempted || app.run();
  });

  if (typeof define === "function" && define.amd) {
    define("Holder", [], function () {
      return app;
    });
  }

})(Holder, window);